Question

Relative decrease in vapour pressure of an aqueous solution containing 2 moles [Cu(NH3)3 Cl] Cl in 3 moles H2O is 0.50. On reaction with AgNO3, this solution will form(assuming no change in degree of ionisation of substance on adding AgNO3)

• A. 1 molAgCl
• B. 0.25 molAgCl
• C. 0.5 molAgCl
• D. 0.40 molAgCl

Answer 1

Answer: (C)

0.5 molAgCl

Answer 2

$\frac{\Delta P}{P}$ =$\frac{ni}{ni + N}$

0.5 = $\frac{2i}{2i + 3}$

i + 1.5 = 2 i

i = 1.5

i = 1 + (y – 1) $\alpha$

1.5 = 1 + (2 – 1) $\alpha$

$\alpha$ = 0.5

mole of Cl– = 1.0

mole of AgCl ppt. = 1.0